Plus change the footer wording + styling a little

Currently hitting this kind of issue (https://github.com/fpco/stackage/issues/3132) when building with Gitlab Pages.
Reverting, so that the build pipeline still works. Will tackle separately in a later commit.

Added descriptions to all pages.
Updated footer to contain link to atom feed
Deleted unused template, and site.hs code
Updated to newer version of hakyll

Plus a readme